package com.lagou.consumer;

import com.lagou.rpc.*;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.UUID;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicInteger;

public class RpcConsumer {

    //创建线程池对象
    private static ExecutorService executor = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());

    private static UserClientHandler userClientHandler;
    private static AtomicInteger requestId = new AtomicInteger(0);

    //1.创建一个代理对象 providerName：UserService#sayHello are you ok?
    public Object createProxy(final Class<?> serviceClass){
        //借助JDK动态代理生成代理对象
        return  Proxy.newProxyInstance(RpcConsumer.class.getClassLoader(), new Class<?>[]{serviceClass}, new InvocationHandler() {
            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                //（1）调用初始化netty客户端的方法

                if(userClientHandler == null){
                    initClient();
                }

                // 设置参数
                //userClientHandler.setPara(providerName+args[0]);
                /**
                 * 构造协议请求
                 */
                RpcRequest req = new RpcRequest();
                req.setClassName(serviceClass);
                req.setMethodName(method.getName());
                req.setParameterTypes(method.getParameterTypes());
                req.setParameters(args);
                req.setRequestId(String.valueOf(requestId.incrementAndGet()));
                userClientHandler.setPara(req);

                // 去服务端请求数据

                return executor.submit(userClientHandler).get();
            }
        });
    }

    //2.初始化netty客户端
    public static  void initClient() throws InterruptedException {
        userClientHandler = new UserClientHandler();

        EventLoopGroup group = new NioEventLoopGroup();

        Bootstrap bootstrap = new Bootstrap();
        bootstrap.group(group)
                .channel(NioSocketChannel.class)
                .option(ChannelOption.TCP_NODELAY, true)
                .handler(new ChannelInitializer<SocketChannel>() {
                    protected void initChannel(SocketChannel ch) throws Exception {
                        ChannelPipeline pipeline = ch.pipeline();
                        //pipeline.addLast(new StringEncoder());
                        //pipeline.addLast(new StringDecoder());
                        pipeline.addLast(new RpcEncoder(RpcRequest.class, new JSONSerializer()));
                        pipeline.addLast(new RpcDecoder(RpcResponse.class, new JSONSerializer()));
                        pipeline.addLast(userClientHandler);
                    }
                });

        bootstrap.connect("127.0.0.1", 8990).sync();
    }
}
